This Pistachio Bundt Cake (famously known as the “Watergate Cake” or “Green Goddess” in retro baking circles) is a magnificent, ultra-moist, and vibrantly colored dessert masterpiece. By infusing a standard white cake mix with instant pistachio pudding, whole milk, and a generous egg count, you create an incredibly tight, velvety crumb that completely avoids the dry texture typical of boxed mixes. Finished with a cloud-like, fluffy pudding frosting made from Cool Whip, it delivers premium, crowd-pleasing results perfect for holidays or casual family gatherings.

 

Pistachio Bundt Cake – Ingredients

 For the Pistachio Cake
1 box (14¼ oz) white cake mix
2 boxes (3.4 oz each) instant pistachio pudding mix
1/2 cup vegetable oil
1/2 cup whole milk
1/2 cup water
5 large eggs

Fluffy Cloud Frosting
1 box (3.4 oz) instant pistachio pudding mix
1 1/2 cups whole milk
1 tub (8 oz) Cool Whip, thawed

 

Step-by-Step Directions:

Step 1: Calibrate and Prepare the Mold: Preheat your oven to 350°F (175°C). Thoroughly grease and flour a standard 12 / cup Bundt pan.

 

Tip: Pay special attention to coating all the intricate ridges and the center tube of the pan with shortening, butter, or a baking spray that contains flour. This creates a reliable barrier so the cake drops out cleanly without tearing.

 

Step 2: Combine the Dry and Liquid Bases: In a large mixing bowl, combine the white cake mix, 2 boxes of instant pistachio pudding mix, 1/2 cup of vegetable oil, 1/2 cup of water, and 1/2 cup of whole milk. Blend with a hand mixer or stand mixer on low speed just until the dry ingredients are fully moistened.

Step 3: Build the Aerated Emulsion: Add the 5 eggs to the batter one / at a time, blending briefly after each addition to incorporate. Once all eggs are in, increase the mixer speed to medium and whip the batter for 1 / to 2 / minutes until it is completely smooth, slightly pale green, and light and airy.

 

Step 4: Execute the Steady Bake: Pour the smooth green batter into your prepared Bundt pan, leveling the top with a spatula. Bake on the middle oven rack for 45 / to 50 / minutes. Test for doneness by inserting a wooden toothpick deep into the thickest part of the cake ring; it must come out clean or with a few dry crumbs attached.

Step 5: The Crucial Inversion Window: Remove the pan from the oven and let it cool undisturbed for exactly 10 / minutes on a wire rack. Gently slide a thin plastic knife or silicone spatula around the outer edges and center tube to loosen any sticky spots. Place your serving plate upside down over the top of the pan, firmly grip both the plate and pan together, and invert them in one fluid motion. Let the pan sit inverted for a minute until the cake slips out cleanly onto the plate. Allow it to cool completely to room temperature.

Step 6: Whisk and Chill the Frosting: While the cake cools, build your topping. In a large bowl, whisk together the remaining 1 box of pistachio pudding mix and 1 1/2 cups of cold whole milk for 1 / minute until completely smooth. Using a rubber spatula, gently fold the 8 ounces of thawed Cool Whip into the pudding mixture until just combined and streak-free. Cover the bowl and refrigerate for at least 40 / minutes to thicken.

Step 7: Enrobe and Store: Once the cake is completely cool to the touch, spread the chilled frosting evenly over the entire surface, covering the top, sides, and inner funnel. Keep the frosted cake refrigerated until you are ready to slice and serve.